Kiln and like structure, and heat treatment



N. LENGERSDORFF KILN AND LIKE STRUCTURE, AND HEAT TREATMENT Jan. l 26 1926.

Filed Feb. 9, 1924 4 Sheets-Sheet 1 1,571,058 N. LENGERSDORFF Filed F eb. 9, 1924 4 Sheefcs-Sheet 2 Jan. 26 1926..

KILN AND LIKE STRUCTURE, AND HEAT TREATMENT L uw www N. LENGr-:RsDoRFF KILN AND LIKEv STHUCTURE, AND HEAT TREATMENT Jap. 26 ,1926.

Filed Feb. 9, 1924 4 Sheets-Sheet 5 CMV.

Jan 9 w N. LENGERSDORFF KILN AND LIKE STRUCTURE, AND HEAT TREATIENT Filed Feb. Q ,j 1924 4 Sheets-shyt 4 F' 4 lg. E.

a' Vr g5' 4 fi I I I r /7 T 70K/VE YS Patented Jan. 26, 1926. i

UNITED STATES NICOLA LNGERSDORFF, F DRESDEN, GERMANY.

KILN AND LIKE STRUCTURE, AND HEAT TREATMENT.

Application led February 9, 1924. Serial No. 691,688.

To a-ZZ Iwhom it may concern:

Be it known that I, NICOLA LENGERS- Doizrr, a citizen of Germany, and resident of Dresden, Germany, have invented certain new and useful Improvements lin Kilns and like Structures, and Heat Treatments, of which the following is a specification.

My invention relates to kilns and furnaces, particularly of the type in which the structure comprises a longitudinal passage or tunnel through which the material 0r the goods to be treated are Caused to travel. The specific embodiment of my invention illustrated by the accompanying drawings has been designed for the treatment ofmaterials or goods which contain more or less moisture which it is desired to'drive out; for instance, the kiln illustrated may be used for the burning of porcelain, bricks of various kinds, tiles and other articles of clay or the like, as well as for the burning of lime. It will be understood, however, that the invention is of. broader application than the specific embodiment and uses expressly disclosed herein.

The object of my invention is to obtain superior results both with respect to the effeet of the treatment on the ware or material and as regards economy in the amount of fuel required. This I obtain by novel arrangements for regulating the supply of the heating agent and for utilizing the heat taken up by the goods or material, as well as by other novel features which will be pointed out hereinafter. e

Reference is to be had to the accompanying drawings, in which Figs. 1, 11 and 1h are fragn'ientary longitudinal central sectionsof the kiln, each of these views being a concinuation of the others, Fig. 1 being the left hand end. Fig. 1a the middle portion,

- and Fig. 1" the right hand end; Fig. 1 is an elevation partly in section showing a gas producer, separator, purifier and cooler;

Figs. 2, 2a and 21 are corresponding fragmentary horizontal sections, substantially on line-s 2--2, :2a-2a and 2"-2b of Figs. 1. 1j and 1*' respectively; Fig. 2c is a plan vieu' of Fig. 1c with parts in section; Fig.

3 is a vertical cross section on line 3-3 of Fig. 1; Fig. 31,. a vertical cross section on line 3 of Fig. 1; Fzg. 4 is a section on line 4 4 of Fig. la; Fig. 41 is a section on line 4-,-4 of Fig. 1n; Fig. 5 is a sectim on line 5-5 of Fig. 1"; Fig. 51 is a section on 55 line 5-5 of Fig. 1*.

At theright-hand end (Figs. 1b and 2b) of the apparatus illustrated, I have indicated at 1 a gas producer of any well-known or approved type, constructed to deliver gas under pressure to a separator 2 for the removal of dust, from-Which the gas passes through a temperature regulator 3 to a disintegrator or purifier 4 of any suitable character adapted to remove from the gas, 35 y any dust remaining therein, as well as the tar contained in the gas. At 5 I have indicated a cooler receiving the'gas from the purifier 4, and at 6 a vaporizer for obtaining the vapor-and-air mixture required for the producer. .7 designates a pressure regu lator contained in the pipe 8 through which the purified gas, under pressure, is conveyed from the cooler 5 to the kiln or furnace proper. The pipe 8, which is a single 'f5 conduit. at first, has two branches where it runs within or along the sides of a kiln proper. At that end of the kiln which is nearest the gas producer, the two branches of the pipe 8 are located within ducts or 80 channels 8a located in the roof of the kiln,

at the sides thereof, and thus the gas flowing through these portions of the pipe 8 1s heated, partly by radiation of heat from the interior of the kiln, and partly by the passage of hot air through the channels 8a, such air being supplied from a recuperator,

as will be explained below. At the main heating zone of the kiln, the two branches 0f the pipe 8 are located exteriorly of the 90 kiln proper (see Figs. 1a and 4) and provided with a plurality of feed tubes 9 having individual independent regulating devices 9 and leading to the respective burners 10 projecting their fiames transversely 95 into the longitudinal passage or tunnel 11 of the kiln. The burner orifices may be arranged in two tiers, and they are disposed exactly opposite each other on the two sides 4of the passage 1 1 so that the two flame jets 190 directed toward each other from the two registering orifices or nozzles of the same pair will meet with their points at the center of the kiln, the gas pressure being adjusted (by the regulators 7 and 9a) to project the flames to this distance, and the ware or material under treatment being stacked or arranged with transverse channels or spaces to allow the flames to be tlms projected.

The ware or material is placed on trucks 12 traveling on a longitudinal track. derneath this track is located a passageway 13 for making inspections and repairs, access to such passageway being had through transverse adits 13". The lnain heating or burning zone into which the flame jets are discharged, is desi nated by 14, while 15 indicates Ithe pre iminary heating zone through which the goods (traveling from left to right accordmg to the showing in the drawings) pass before they reach the main heating zone 14.

From the preliminary heating zone 15 smoke and moist air are carried away through outlets 16 and 16b located at different points of the length of said zone. These outlets are provided with independent dampers or other regulating devices so that the draft may be adjusted for the outlets 16 independently of the outlets 16", and vice versa. 'Io this preliminary heating zone, hot air (from a source referred to below) is delivered through individuall \Y regulatable channels 17. The outlets 16a and 16b are connected by ducts 18 (controlled by suitable individual regulating devices) with the suction inlet of afan or blower 19 which forces the smoke etc. into the stack 20.

At the end of th'e kiln nearest to the gas producer 1 is located the cooling zone 21, and at the junction of this zone with the main heating zone the passage 11 is formed with lateral enlargements 22. in which the hot air within the passage 1l may expand so that it may travel more readily to the burners through the path to be described presently. From the lower portion of the enlargements 22 longitudinal channels 23 conduct the hot air to branch ducts 23, Iprovided with individual re ulating devices 23h and deliverin heated air, in adjustable amounts, to the individual burner nozzles (see the left-hand portion of Fig. 4).

Another supply of air is taken in at inlets 24a'and passes through heaters or recuperators 24 located in the side walls of the kiln (to the right of theV enlargements 22, Figs. 1 and 2") to a channel consisting of sections 25, 25, 25 located in the roof of the kiln and connected with the air delivery channels 17. Suitable regulating devices are provided in this connection also, as mentioned above.

Uni Adjacent to the cooling zone 21 of the kiln radiators 26 are shown, located in the side walls, so as to cool the inside of the kiln and at the same time heat the water or air contained in the radiators, such water or air being used for any pur ose desired` for instance the hot air thus o )tained may be used for drying.

The trucks 12 may be moved along' the passage 11 by any well-known or approved pushing or pulling device, indicated diagrammatically at 27. The kiln is also provided with suitable doors or flaps at the ends of the longitudinal passage 11.

1t will be understood that the structurr of the kiln proper is absolutely symmetrical with reference to the longitudinal central plane in which Figs. 1, 1n and 1b are taken, that is to say, the arrangement of the kiln parts to the left of such plane is exactly the same as ou the right of said central longitudinal plane.

The material or goods enter the kiln passage 11 at one end and travel therethrough gradually to the other end, at which they emerge from the kiln proper.

One of the important characteristic features of my invention is the use of purified gas under pressure, the supply of such gas being regulatable independently for each individual burner, and the air for supporting combustion being fed to each burner in a heated condition, by the suction which the stream of gas exerts, and such air supply is preferably also regulatable independently for each individual burner. The drawings indicate regulating devices at various oints of the apparatus, enabling the o eration to be controlled very accurately. heburners 10 are preferably annular burners made of refractory material (tireclay or the like).

The utilization of heat is very thorou h in my kiln. which is evidenced by the reilltively low temperature of the gases leaving the kiln at 1S. Then the kiln is employed for burning orcelain, I find that the temperature of t le gases drawn ofl al. 18 will average about from 100 to 120 centigrade. More particularly, the losses due to incomplete combustion are very slight.

It will be noted that 1 reco-ver a considcrable portion of the heat supplied to the main heating zone, and utilize the heat thus recovered, for the preliminary heatin of the material or goods on the way to suc mam heatmg zone. Thus. 1f the kiln 1s used for burning porcelain, the heat. applied in the preliminary heating zone will Aserve to dry the clay and to convert it into porcelain. Tests show that in a kiln constructed ac cording to my invention, about 12% of the total heat etl'ect is required for this preliminary heating. The latter operation is performed by means of heat abstracted from the cooling zone of the kiln. I have found lIU ished material or goods as the result of the main heating operation will be sufiicient for `the hot air in heat that will heat-ing the air which is fed to the burnersV for supporting combustion. The remainder of the heat present in the cooling zone is utilized for kthe preliminary heating operation; this` may be done in the -indirect manner -described above, with the aid of. a recuperator such as 24, or, instead of this, a portion of the passageway 11, may be withdrawn through a by-pass and diverted to the channels 17, in substantially the same manner that hot air is led to the ducts 23a.

It will further be noted that the channels 17 for the admission of hot air are located between the two 'sets of outlets 16a and 161 through which the moisture and gases are withdrawn. By this arrangement I am enabled to remove material under treatment, without any in-` jury to said goods or material, and this is of special importance when the material contains a relatively large amount of moisture. The success of this drying operation is assisted materially by the attendants being able to adjust individually, not only the sets of outlets 16lL and 16h, but the, air inlets`17 as well.

.By the arrangementsshown and described,

I am enabled tofutilize the heat most. ef-

gas in such a-inanner as to secure, at each point of the assa ewa 11the degree of Isecurge theybest results at such point. 'The amount of pressure for the proper operation of the burners, is relatively small. ach burner discharges the gas in the @form of an annular jet, which will en- `than if the mixture of air in such passage,

lthe proper flow of train'an annular stream of hot air. It will be notedv that the gas and the air for supporting combustion are well mixed with each other before they' enter the passage 11, and in this manner I obtain much better results and gas took place as it does in some earlier constructions.`

The heatingin zones, vwhich is 4a characteristic feature of my invention, is obtained in'a manner'-yvhich does not interfere vwith v the hot air in the passage 11; this independence offsaid two' features is due chiefly to the provisionv of the lateral enlargements22, ,which release the hot air so that, by th suction exerted by the individual gas jets, such-air may be brought to the several'burners. When gas and air are both hot and in the shape of annular jets or streams,'the velocity with whichthe` y resulting mixture flows is greatly increased.V Thus,` for instance, if the gas pressure is equalcto that of a column of water of a height of from 6 to 7 millimeters, and if the interior Width of the kiln is six feet, the points moisture fromthe goods or f l portion of the kiln .character of the material and particularly lpurpose thatI have provided of the two fiame jets discharged in opposite directions from transversely registering burner nozzles will meet in the longitudinal central plane of the passage 11, each fiame (measuring from the tip of the respective burner l0) having a length of about five feet.` It will be noted that theyburner tips are at a` relatively considerable distance (abou two feet) from the passage 11, so that ga and air will have ample vopportunity for mixing before they reach the passage 11, thus insuring a thorough mixture; and the fact that these two constituents are hotat the time of their mixture, enables me to carryout the 'heating operation in readily regulatable the various desired effects on under treatment, such as a rea neutral effect or an oxidizcarried by the trucks is preferably arranged loosely, so as to present slitsboth horizontally and vertically, especially at the lower and between neighboring trucks.

In a kiln constructed according to my in- Vention .and used for burning porcelain at a temperature of 14.00 degrees centigrade, the temperature of the air withdiawnfrom the cooling zone, for use at the burners, was found to be 1000 degrees centigrade. This indicates' a very large recovery of heat and explains the relatively small percentage of the heat required for the' preliminary heat- 1isng (drying and porcelain-forming) operaion.

The particular zone heating system del scribed valso enables me to withdraw the waste gases, in a regulatable manner, at those points of the preliminary heating zone at which the respectivevgas poi-tions have accomplished the desired result. j The possibility of thus regulating the withdrawal of the' waste gases is of considerable importance in view of the fact that their saturation point (that is,the point at whicli`tliey are una-ble to `take up any further amount of moisture)-is reached at different points of the length ofthe kiln,

under treatment, on the degree of moistune contained in such material. L It is for this a plurality of independently regulatable outlets (such as 16a and\16")` at different points of the length of the preliminary heating zone.

Other advantages .of the zone heating system described herein are as follows: It

enables hot air for supporting combustion to under treatment has been depending on the t burned o1' otherwise treated to the desired.

point but is still very hot, such hot air being taken off through the enlargements 22, as described. I may also heat Vair by radiation (as in connection with the recuperator 24) and bring such heated air, as described, to the-preliminary heating zone in order to dry or preheat the goods or material under treat'- ment. In the cooling zone air or Water contained in the radiators 26 may be heated and then conducted to a place of use, for instance for drying operations.

Instead of purified gas, I may employ oil (under pressure) as the fuel supplied to the burners. v

When using the zone heating system described, the burners l() are adjusted from the outside of the kiln until the points of the opposing flame jets' meet at the center of the kiln passage.

The heating arrangement may be extended or shifted horizontally as well as vertically.

With this zone system of heating, therefore, the heating devices are quite independent of the open longitudinal passage 11, since the hot air for supporting combustion is supplied to each of the burners in individually regulatable amounts. While the heat- Ving system is thus independent, it is desirable, in order to obtain the best results, to maintain a practically uniform composition of the heating gas or other fuel, and also to regulate the draft through the kiln and keep it' constant by means of a blower or other I suitable device. In this case, the kiln-would operate under the following especially favorable conditions: First, fuell (and particularly heating gas) of uniform composition, temperature and pressure; second, constant draft; and third, a temperature uniform within each of the several zones of the kiln. Various modications may be made Without departing from the nature of my invention as set forth in the appended claims.

I claim as my invention:

1. Theprocess of treating goods or ma- I terial, which consists in heating them by llames, then carrying them away from such flames` into contact with air to be heated by such hot material, and then carrying such heated air, in amounts, to the several llames, to support combustion, the amount of heated air delivered to each flame being independently regulated with respect to thev llame which it serves.

2. TheV processof treating goods or material, which vconsists in passing them betweemand in direct contact with flame jets directed totgard each other transversely of the path of said material and of such length as to cause the points of opposed jets to meet at ltlhe longitudinal central plane -of said pat 3. The process of treating goods or material, which consists in passing them first through a. preliminary heating zone, then through a main heating zone, and finally through a cooling zone, utilizin the heat prevailing in said cooling zone, or heating air, leading the air thus heated to the preliminary heating zone, and withdrawing gases from said preliminary heating zones at points both in advance and in the rear of the region at which heated air is admitted Ito said preliminary heating zone.

4. A kiln or vlike structure having a longitudinal passage, burners adjacent to one portion of said passage, connections for taking heated air from another portion of said passage and leading such air to said burners, and air-regulating devices associated with the several burners for independently regulating thc air supply to each of said burners.

5. A kihrorlike structure having a longi. tudinal` passage, burnersv adjacent to one portion of said passage, connections for taking heated air from another portion of said assavc and leadiner such air to said burners i individual fuel-regulating devices associated with the several burners, and air-regulating devices associated with the several burners for independently regulating the air supply 'to each of said burners. v

6. A kiln or like structure having a longitudinal passage with lateral enlargements constituting expansion chambers for heated air, burners located adjacent to a portion of said passage, to one side of said enlargements, and connections for leading the expanded heated air from said enlargements to the burners. 4

7. A kiln or like structure having a longitudinal passage, heating means located adjacent to one portion of said passage, air-heating means located adjacent to a portion of the passage to one side of the first-named portion, air-inlets located at a portion of said passage on the opposite side of the said first-named portion, and connections for leading hot air from said air-heating means 'to said air-inlets.

8. A kiln or like structure having a longitudinal passage with hot-air inlets at one .portion thereof, Wastel gas outlets both in advance and in the. rear of said inlets, and heating means adjacent toa portion of the passage in advance of saidv inlets and outlets.

9. 'A kiln or like structure having a longitudinal passage with hot-air inlets at one portion thereof, waste gas outlet-s both in advance and in the rear of said inlets, inde-v pendent regulating means for the outlets lo- Y cated in advance of the inlets and for those located in the rear thereof, and heating means adjacent to afportion of the passage in advance of said inlets and outlets.'

lll)

10. A kiln ,or like structure having a tion of the passage in advance of the secondvided with burners receiving purified gas named portion. under regulated pressure, from saidl proll.Adevice ofthe character deseribed,co1n ducer and purifier. 10 prising:r n gas producer, gas-purifying means In testimony whereof I have signedl this 5 connected with the outlet of said producer, a specification.

device for regulating the pressure of the vpurified gas, and a, kiln or like structure pro- NICOLA LENGERSDORFF. 

